This invention relates to slide fasteners, and in particular to slide fasteners adapted for unopenably closing openings in upholstery coverings of chairs, sofas and like articles. Even more particularly, the invention deals with improvements in a slider for use in such fasteners.
The slide fasteners employed for the above application have usually been provided with sliders of the automatically locking or cam-locked type, such that the sliders can be locked against movement in the fully closed position on the interlocking rows of fastener elements. These sliders, however, have originally been developed for use on fasteners applied to plackets and other closure openings in garments, bags and the like. In the sliders of both known types a locking pawl is provided which is actuated by the pull tab into and out of engagement with the fastener elements in the guide channel in the slider body.
The slide fasteners incorporating such conventional sliders are therefore readily openable, after having been closed, by manipulating the pull tab in the usual manner. Thus, when such fasteners are applied to openings in upholstery coverings of chairs and the like, they may be opened, for example, by children out of curiosity. This is undesirable since then the rubber sponge or like filling material within the coverings can be easily taken out.